This invention relates to the electronic control of mechanical actuators and particularly to the remote control of hydraulic or pneumatic valves such as used on cranes or other heavy equipment.
Substantially all heavy equipment is hydraulically operated and employs a bank of manually operated valves for controlling the application of high pressure fluid to the various hydraulic cylinders that apply the necessary high forces to position or operate the equipment. In many instances it is important that the operating engineer of such hydraulic equipment is located at some position that is remote from the bank of manual control valves. For example, a precise positioning of an article supported by a crane may require the crane operator to position himself next to the article and to operate the hydraulic valves by some remote controlling system such as disclosed in my U.S. Pat. No. 4,240,304. Or, an explosive device or some article located in an explosive or hazardous atmosphere may be positioned by an operator at a remote location by a remote control system such as disclosed in my pending U.S. application Ser. No. 183,020, filed Sept. 2, 1980, now U.S. Pat. No. 4,306,314. Both of these remote valve control systems provide for the actuation of one valve at a time and also the total cessation of operation upon the release of a deadman switch on the remote control unit.
The present system differs from the prior systems mentioned above in that an indefinite number of cylinder controlling hydraulic valves may be individually and simultaneously positioned from the remote location while a deadman switch is depressed. Or, if desired, any or all of the hydraulic control valves may be preset by the operator at the remote location and then simultaneously actuated by the closing of the deadman switch.